Hi Nirit 

Thanks for reaching out in the Lucidchart Community! In order for you to join the team you will first need to accept the invite that has been sent to your email. Would you mind checking your spam folder just in case your email client filters out the invite email from us? 

As for the issue with shared libraries to access shared team libraries please open the Shapes section of the Workspace Manager and click the triangle next to "Shared With Me" in the bottom left corner. A list of all shared team libraries will expand. However keep in mind that you will have access to any shared libraries only once you have successfully joined the team you have been invited to.
 

For more information please read through our Shape Libraries article from the Lucidchart Help Center. Hope this helps!